<template>
	<div>
		<router-link 
			tag="div" 
			to="/" 
			class="header-abs"
			v-show="showAbs"
		>
			<div class="iconfont header-abs-back">&#xe624;</div>
		</router-link>
		<div 
			class="header-fiexd" 
			v-show="!showAbs"
			:style="opacityStyle"
		>
			<router-link to='/'>
				<div class="iconfont header-fiexd-back">&#xe624;</div>
			</router-link>
			景点详情
		</div>
	</div>
</template>

<script>

export default {
	name: 'DetailHeader',
	data () {
		return {
			showAbs: true,
			opacityStyle: {
				opacity: 0
			}
		}
	},
	methods: {
		handleScroll() {
			// console.log(scroll)
			const top = document.documentElement.scrollTop
			// console.log(document.documentElement.scrollTop)
			if (top > 60){
				let opacity = top / 140
				opacity = opacity > 1 ? 1 : opacity
				this.opacityStyle = { opacity }
				this.showAbs = false
			}else {
				this.showAbs = true
			}
			
		}
	},
	activated () {
		window.addEventListener('scroll',this.handleScroll)
	},
	deactivated () {
		window.removeEventListener('scroll',this.handleScroll)
	}
}	
</script>

<style lang="stylus" scoped>
@import '~styles/varibles.styl'
	.header-abs
		position: absolute
		left: .2rem
		top: .2rem
		width: .8rem
		height: .8rem
		line-height:.8rem
		border-radius: .4rem
		text-align: center
		background: rgba(0, 0, 0, .8rem)
		.header-abs-back
			color: #fff
			font-size: .4rem
	.header-fiexd
		z-index: 2
		position: fixed
		top: 0
		left: 0
		right: 0
		height: $headerHeight
		line-height: $headerHeight
		text-align: center
		color: #fff
		background: $bgColor 
		font-size: .32rem
		.header-fiexd-back
			position: absolute
			top: 0
			left: 0
			width: .64rem
			text-align: center
			font-size: .4rem
			color: #fff
</style>